In vivo and in vitro dendritic signalization with JEDI-2P combined acousto-optical imaging

Newly developed voltage indicators require fast scanning methods for effective signal recordings. The flexibility of AO imaging allows us to measure in a three-dimensional volume not only at the somatic level, but also the dendrites. Their high scanning frequency makes AO microscopes suitable for dendritic signal processing and plasticity research. Soma dependent and independent dendritic activities are highly investigated areas, but the spatio-temporal limitations of electrophysiology and conventional one- or two-photon devices have serious constraints when it comes to GEVI imaging. Here we show AO imaging on GEVI (JEDI-2p) labelled pyramidal cell somas and dendrites, combined with electrophysiology and glutamate uncaging. Voltage signals are compared to electrophysiology data from patch clamp recordings in vitro. We used the glutamate uncaging to describe soma independent dendritic signals, by stimulating different dendritic segments. In the in vivo condition, we measured innate, ordinary activity at the somatic and dendritic levels. We captured not only the action potential level of activity from both somata and their dendrites, but even the subthreshold events were detected. Here we prove that the AO microscope combined with GEVIs can be a suitable and optimal tool in the synaptic integration field.